package model;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

// 通过UserDao完成 user 表的操作
public class UserDao {
    //1. 根据userId 来查到对应的用户信息
    public User getUserById(int userId){
        Connection connection = null;
        PreparedStatement statement = null;
        ResultSet resultSet = null;

        try {
            connection = DBUtil.getConnection();
            String sql = "select * from user where userId = ?";
            statement = connection.prepareStatement(sql);
            statement.setInt(1, userId);
            resultSet = statement.executeQuery();
            if(resultSet.next())
            {
                User user = new User();
                user.setUserId(resultSet.getInt("userId"));
                user.setUsername(resultSet.getString("username"));
                user.setPassword(resultSet.getString("password"));

                return user;
            }
        } catch (SQLException throwables){
            throwables.printStackTrace();
        } finally {
            DBUtil.close(connection, statement, resultSet);
        }
        return null;
    }

    //2. 根据username来查到对应的用户信息
    public User getUserByName(String username){
        Connection connection = null;
        PreparedStatement statement = null;
        ResultSet resultSet = null;

        try {
            connection = DBUtil.getConnection();
            String sql = "select * from user where username = ?";
            statement = connection.prepareStatement(sql);
            statement.setString(1, username);
            resultSet = statement.executeQuery();

            if(resultSet.next())
            {
                User user = new User();
                user.setUserId(resultSet.getInt("userId"));
                user.setUsername(resultSet.getString("username"));
                user.setPassword(resultSet.getString("password"));

                return user;
            }
        } catch (SQLException throwables){
            throwables.printStackTrace();
        } finally {
            DBUtil.close(connection, statement, resultSet);
        }
        return null;
    }
}
